follow up: it all began with sewage backing up in our the sownstaris showe--plumber came and claened out the pipes with a snake and then the plumber cleaned out the septic system and then placed the 27 inch risers on and the lids--a few days later we still had a problem with back up and we had a guy come wiht a camera and he said we had roots in our line and recommended replacing the ceramic tiles with plastic so we did--after all of that we started noicing the smell--so the plumber came out and said it was the sink drying out (the trap) well I use that sink everyday and have for years we have never had a problem until we had all of this work done--I did go ahead last night and put the old lids back on with the help of others and the problem still remains althought today it is not as heavy of a smell or god forbid I am getting use to it--so not what? thanks: : thanks for the past post about my problem I wanted to ask--I had 27 inch risers installed on my septic system--they did not replace the original lids back in the holes (in the ground) only new lids on the risers--I was wondering could the gap of air between the septic system and the risers cause the gas smell--that might be a stretch but I wanted to ask as I have put out a lot of money lately and I am hoping to get help here and solve the problem--so should I put back on the old lids on top of the holes and then the lids to the risers?--also would it take a long time for the smell to leave my house once I do find the problem--if I ever do: : thank you

: : If the lids aren't on the tank the air around the tank would be unpleasant but it wouldn't cause the problem in the house unless the wind is blowing it in.If the smell is coming from the traps then it sounds like they are being siphoned out which points to a venting problem.Can you explain a little more about what your plumber replaced?